The service, in which two trolleys will loop the city on separate routes, is designed to give residents an easy way to travel to stores, schools, city parks and recreation centers, churches and medical offices, according to officials.

Mayor Sarann Kruse said the trolley buses will be especially helpful to senior citizens who do not drive, and to youngsters who must now cajole their parents into driving them to schools and parks.

The buses, designed to resemble the fabled "Big Red" trolley cars that used to serve the Los Angeles area, operate from 7 a.m. to 7 p.m. weekdays and 8 a.m. to 6 p.m. weekends. One travels on the west side of the city and the other on the east side, with Hawthorne Boulevard as the dividing line. Both start and end their routes at Civic Center and both go to the new South Bay Galleria shopping mall. Each route takes 35 minutes to complete.

The system is being financed through the city's share of a county transportation tax approved by the voters in 1981.